What type of defect does porosity in metals typically indicate?

Porosity in metals typically indicates low tensile strength due to the presence of voids or pores within the material. When small gas bubbles or voids form during the solidification process, they can compromise the integrity of the metal, leading to a reduction in its overall strength. The presence of these pores disrupts the uniform structure of the metal, making it less able to withstand tensile forces.

While improper cooling might also be a factor in creating other types of defects, porosity directly correlates with the mechanical properties of the metal, particularly impacting its ability to resist deformation and failure under tension. High ductility, which refers to a material's ability to deform without breaking, is generally not related to porosity; in fact, excessive porosity would typically lead to reduced ductility. Similarly, excessive alloying may change certain properties of the metal but does not necessarily result in porosity as a defining defect. Therefore, the connection between porosity and low tensile strength stands out as the primary concern regarding the performance and reliability of metal components.